Hydrochloric Acid → (4-amino-1-{4-[(methylsulfonyl)amino]butyl}-1H-imidazo[4,5-c]quinolin-2-yl)methyl L-valinate

Participants

Reaction Steps

To a hydrogenation bottle was added (4-amino-1-{4-[(methylsulfonyl)amino]butyl}-1H-imidazo[4,5-c]quinolin-2-yl)methyl N-[(benzyloxy)carbonyl]-L-valinate (1.5 g, 2.5 mmol) followed by a mixture of methanol (30 mL), THF (15 mL) and water (5 mL) and conc HCl (5 mL). To this was added Pd/C (90 mg) and the reaction was hydrogenated at 40 psi (2.8×105 Pa) overnight. To the reaction mixture was added conc. HCl (5 mL) and Pd/C (90 mg) and the reaction was hydrogenated at 40 psi (2.8×105 Pa) for 18 hours. The reaction was filtered through CELITE filter aid and the filtrate was evaporated to afford a clear oil. The product was isolated by prep HPLC (ISCO Combiflash Separation System, Biotage Si 40+M column, eluted with a gradient of 0-8% methanol in dichloromethane with 1% ammonium hydroxide) to provide (4-amino-1-{4-[(methylsulfonyl)amino]butyl}-1H-imidazo[4,5-c]quinolin-2-yl)methyl L-valinate (0.495 g) as an off white solid, mp 161-163° C.; MS (ESI) m/z 463 (M+H)+; Anal. Calcd for C21H30N6O4S: C, 54.53; H, 6.54; N, 18.17; Found C, 53.96; H, 6.62; N, 17.85, delta C=0.57.

Provenance & Evidence